Do I need a new power brake booster?

[MaximRecoil]

I hear a hissing/leaking sound when I use the brakes in my '69. The strange thing is: it doesn't leak when you aren't touching the brake pedal, and it doesn't leak when you press hard on the brake pedal ... it only leaks (air hissing sound) when you press lightly or moderately on the brake pedal. Does the booster have to be replaced or is it something that can be fixed?

Also, I have drum brakes all around, but I plan to convert to front disc brakes eventually. Do you need a different booster for disc brakes than the type that came on drum brake cars?

[jaak]

Also, I have drum brakes all around, but I plan to convert to front disc brakes eventually. Do you need a different booster for disc brakes than the type that came on drum brake cars?

Someone else will have to chime in on the first question. But Yes disc brake cars had a Bendix brake booster (drum booster was a Midland Ross). They are difficult to find, and pricey when you do. I bought a core from a member on here for 75, and sent it to Prior Brake in Texas to be rebuilt. They charged around 115 (that included return shipping), that was 6-7 years ago though, their prices may have increased.

Bendix booster when I installed it on my car...


Jason

[Dino]

I'm not sure on the hissing.  Does the brake system still work properly, at this point is it solely a sound issue?  Curious to what this could be.

It's indeed a different booster, but the drum booster should still work.  I plan on using the Wilwood kit that came with the car in boxes with the drum booster. I think the diameter of the master cylinder rod will be more of a factor.

Eventually I'd like to get a hydroboost unit and +-12" discs but I'm dreaming now.

[MaximRecoil]

I'm not sure on the hissing.  Does the brake system still work properly, at this point is it solely a sound issue?  Curious to what this could be.

The brakes work properly; the booster gives plenty of "boost". The brakes are actually on the touchy side; it is easy to push them too hard and jerk to a halt. The hissing sounds like an air leak, like an air tool connected to a hose with a leaky connector. I think it is strange that the hissing stops when you press the brakes hard; you'd think that would make it leak worse.

It's indeed a different booster, but the drum booster should still work.

Yeah, that's what I was wondering about, i.e., the functional compatibility.

[MaximRecoil]

You can see/hear what it is doing in this video:

http://youtu.be/KSmh7GlH6hw

It has done that ever since I got it on the road in 2011.